Acoustic transmitter and implantable receiver

Abstract

Among other things, in general, an acousto-mechanical transducer for the interconversion of electricity and acoustic waves is described. Methods are also described for the construction of such transducers.

The invention claimed is: 
     
       1. An acousto-mechanical transducer for the conversion of electricity into acoustic waves or vice versa, the transducer being attached to an active implantable medical device, the transducer comprising a body of piezoelectric material having a front and a back; and the transducer further comprising a backing spacer that contacts the body of piezoelectric material only at its periphery so as to maintain a space spanning the back of the body of piezoelectric material, in which: (i) the back of the body of piezoelectric material has a continuous portion, (ii) the front of the body of piezoelectric material has pillars of piezoelectric material that protrude from the continuous portion of the body of piezoelectric material and that are surrounded by a filler material, and (iii) the pillars are electroded such that each of the pillars is in an electrically isolated region. 
     
     
       2. The transducer of  claim 1  in which the body of piezoelectric material comprises single-crystal relaxor-PT ferroelectric material. 
     
     
       3. The transducer of  claim 1  in which the body of piezoelectric material comprises PMN-PT. 
     
     
       4. The transducer of  claim 1  in which the body of piezoelectric material is curved. 
     
     
       5. The transducer of  claim 1  in which the body of piezoelectric material is shaped as a spherical cap. 
     
     
       6. The transducer of  claim 1  in which the medical device is a hearing aid. 
     
     
       7. The transducer of  claim 1  in which the medical device is a cochlear implant.